Re: FYI: lalr1.cc: Move tokens and YYSTYPE into the class

[Hans Aberg]

On 5 Oct 2005, at 08:57, Akim Demaille wrote:

> > > > "Hans" == Hans Aberg <address@hidden> writes:
>
>
> > On 3 Oct 2005, at 21:23, Paul Eggert wrote:
> >
> > > http://lists.gnu.org/archive/html/bison-patches/2005-09/ 
> > > msg00114.html
>
>
> > Thank you. I looked for it, but could not find it.
>
>
> > It looks fine to me -- I did something similar in my skeleton
> > file. :-) (I got worried that the token or semantic value definitions
> > would have been in the parser class.)
>
> Which is indeed the case.

When the user defines YYSTYPE via a macro, it looks like you only  
have a semantic type declaration within the parser class. I see that  
you have put the union definition within the class, as well as the  
token values.

It worries me that this latter might cause problems when used with  
Flex in a traditional C/C++ header style setup. One then needs (I  
think) in the lexer class to know the size of these types, which is  
not possible if they are put in a class coming after it. This move  
would cause having to work with references in the lexer class.

So the token enum or struct, as well the union definition should be  
put in a special header so that one can, in the lexer source file,  
write:
  #include "<token_header>" /* contains union in applicable cases */
  #include "<lexer_header>"
  #include "<parser_header>"
One can perhaps not achieve this with the current Flex lexer header;  
I tweaked mine.

  Hans Aberg